1. Field of the Invention
The invention relates to communication networks. More particularly, the present invention relates to a system and method for providing preferential access to a multiple access communications medium.
2. Background of the Related Art
The importance of bringing broadband communications the “last mile” so that the benefits of broadband communications can be provided to a home environment has been recognized. More recently, the “last foot” has been recognized as being an enabler for broadband communications in a home environment. That is, it is not enough to merely bring broadband communications into a home, broadband communications must be brought to each individual communicating device within a home for broadband communications to be useful. Home Networking (HN) accomplishes the “last foot” and, therefore, is gaining increasing importance. Home Networking (HN) differs from traditional networking, such as the networking utilized in an office and/or business environment, in that it is more cost sensitive than traditional networking. That is, homeowners are usually more sensitive to the costs associated with installing networking technology than are businesses. Additionally, HN must be simpler to install than traditional networking because it is unlikely that a home environment has been configured for accommodating a traditional business networking technology, such as an Ethernet, which requires special wiring. The cost of installing special wiring is likely to be prohibitive for a homeowner, as will be the complexity of a traditional network installation. Further, because a homeowner does not usually have access to a trained staff of technicians for maintaining a networking infrastructure, HN technology must be simpler to use and maintain than a traditional network environment.
Consequently, HN technologies have been developed that do not require installation of special wiring. For example, one HN technology utilizes a wireless communication medium. Another HN technology utilizes power lines for the communication medium. Yet another HN technology utilizes telephone lines (or more properly, an arbitrary set of electrically connected pieces of telephone wire) as the communication medium. Such a telephone-wire-based HN will be referred to herein as an HPN.
In particular, one telephone line-based HN technology, referred to as HomePNA 2.0, is defined by a proprietary specification developed by the Home Phoneline Networking Alliance (HomePNA or HPNA)). HomePNA 2.0 (HPNA v2 or simply v2) utilizes a distributed multiple access technique for sharing an HN communications medium (i.e., a telephone line) between multiple stations (STAs). As used herein, the term v2 refers to any version of the HomePNA specification having a version number beginning with 2. For example, a HomePNA version number 2.03 or version number 2.1 can simply be referred to as “v2”. Also, a station (STA), as used herein, means any device containing an “adaptor” for allowing the device to communicate over the HN medium. As used herein, an adaptor adapts data for transmission on an HPN medium.
The HPNA v2 distributed multiple access technique supports prioritized access so that time-critical information, such as packets relating to a telephony application, can receive priority over information that is less time-critical, such as packets relating to a web browsing application. While the distributed method of HPNA v2 provides the advantages of “differentiated services” via prioritization, HPNA v2 does not provide a mechanism for enforcing traffic/capacity allocation on the medium. HPNA v2 is also inefficient because packets from different stations can collide, thereby consuming time on the medium without conveying any information.
Consequently, what is needed is a way for enforcing traffic/capacity allocation on an HN communication medium. Additionally, what is needed is a way to make an HN communications medium more efficient by avoiding or reducing packet collisions. Lastly, what is needed is a way for a station operating in a decentralized multiple access environment, such as an HPNA networking environment, to gain priority access in a centralized manner to an HPN communications medium over a v2 STA existing in the same HPN networking environment.